NewGasMet -  Flow Metering of Renewable Gases (Biogas, Biomethane, Hydrogen, Syngas and Mixtures with Natural Gas):  Effect of Hydrogen Admixture on the Accuracy of a Rotary Flow Meter

With the rise of hydrogen use in the natural gas grid a need exists for reliable measurements of the amount of energy being transported and traded for hydrogen admixtures. Using VSL’s high-pressure Gas Oil Piston Prover (GOPP) primary standard, the effect of mixing hydrogen with natural gas on the performance of a high-pressure gas flow meter was investigated. The error of a rotary flow meter was determined using the best possible uncertainty, by calibration with the primary standard for high-pressure natural gas flow. The rotary flow meter was calibrated using both natural gas and hydrogen enriched natural gas (nominally 15% hydrogen), at two different pressures: 9 and 16 bar. Results indicate that, for the rotary flow meter and hydrogen admixtures used, the differences in the meter errors between high-pressure hydrogen-enriched natural gas calibration and high-pressure natural gas calibration are smaller than the corresponding differences between atmospheric pressure air calibration and high-pressure natural gas calibration.